The present invention relates to dental polymerizable composite materials (curable dental compositions) comprising one or more plasticizers comprising a tricyclic structural element, to dental materials (polymers), obtainable by curing the dental polymerizable composite materials comprising one or more plasticizers comprising a tricyclic structural element, to processes for producing a dental material and to dental curable composite materials for use in a therapeutic method in the production of a dental material.
The materials obtainable from the curable dental compositions are particularly suitable as filling materials, core build-up materials, temporary crown and bridge materials, luting cements, relining materials, conditioners, dental materials, modeling materials, base materials, covering compositions for gingiva protection, prosthetic materials, as materials for a temporary supraconstruction for a dental implant or of a core for a temporary supraconstruction, or as inlays, onlays and veneers.
According to the indication, the dental compositions can be used in forms ranging from thin flowing materials as far as thick pasty formulations. Dental compositions generally cure by free-radical means and comprise, as well as the crosslinkable monomers and the initiators/catalysts, also fillers and specific additives which assume quite different functions. As well as free-radical curing, there are also other forms of curing, for example drying in oral release or lacquer systems for production of a carrier for dental active ingredients, or the setting of an initially liquid wound dressing for protection of the mucous membrane.
A very specific additive in curable dental compositions is that of the organic substances which are chemically inert with respect to the reactive components, also called inert solvents or plasticizers. According to the field of use, structure and amount, the inert organic substances or plasticizers meet different requirements.
Plasticizers in polymerizable dental compositions are thus well known from the prior art.
Within the context of the present text the term “(meth)acryloyl” is understood to mean both “acryloyl” and “methacryloyl”.
DE 101 47 125 A1 describes resin compositions for a soft base material. The components used to date for plasticization of a cured material in the resin compositions for a soft base material have been phthalate-based plasticizers; the publication proposes alternative plasticizers, since it is now known that phthalates, being endocrine disruptors, can possibly adversely affect the human body. The application discloses, as plasticizers, acid esters selected from the group consisting of trimellitic esters, fatty acid esters, acetic esters, maleic esters, fumaric esters and citric esters. Explicit mention is made of tri-2-ethylhexyl trimellitate, dimethyl adipate, dibutyl adipate, diisobutyl adipate, diisonorbornyl adipate, di-2-ethylhexyl adipate, diisodecyl adipate, diethylene glycol adipate, dibutyl diglycol adipate, di-2-ethylhexyl azelate, dimethyl sebacate, dibutyl sebacate, di-2-ethylhexyl sebacate, methyl acetylricinolate, epoxidized soyabean oil, glyceryl triacetate, 2-ethylhexyl acetate, dimethyl maleate, dibutyl maleate, di-2-ethylhexyl maleate, dibutyl fumarate, di-2-ethylhexyl fumarate, trimethyl citrate, triethyl citrate, tripropyl citrate and triisobutyl citrate.
Among these compounds, preference is given to diisobutyl adipate, diisobornyl adipate, dibutyl sebacate and tributyl citrate. These compounds can be used individually or in mixtures for production of a soft base material, and they are unable to act as endocrine disruptors in bodies of life forms. The amount of the plasticizer should be between 20 and 80% by weight based on the total mass of the soft base material. If the amount is below 20% by weight, the softness imparted to the composition after polymerization is insufficient; if the amount is more than 80% by weight, the composition becomes too soft for a soft base material.
The resin compositions are used in the form of powder/liquid, liquid/liquid or paste systems in different mixing ratios.
EP 1 194 110 B1 discloses two-component paste/paste systems as temporary crown and bridge materials, which are formulated in a mixing ratio of base paste to catalyst paste of 10:1. Such systems also comprise plasticizing additives. The polymerizable dental composition comprises plasticizers in amounts of 1 to 30% by weight, preferably 1 to 20% by weight and especially 1 to 15% by weight, based on the total mass of the constituents. Suitable plasticizers are polyethylene glycol derivatives, polypropylene glycols, low molecular weight polyesters, dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, diphenyl phthalate, di(isononyl) adipate, tricresyl phosphate and silicone oils.
In the examples of this publication, 2,2-bis-4-(2-hydroxyethoxyphenyl) propane bisacetate is used as the plasticizer in the catalyst pastes.
DE 32 46 654 A1 describes non-adhesive dental impression materials. In these systems, the starter component of the impression materials is used together with plasticizers, and examples of suitable plasticizers are said to be phthalic esters, acylated citric esters, polyglycols, dibenzyltoluene or polyethoxylated sorbitan esters.
DE 101 26 476 A1 (or DE 102 35 990 A1) relates to N-alkylaziridino prepolymers which are used in dentistry for impression materials. The impression materials also comprise plasticizers. For instance, the publication describes plasticizers of the ester type, such as C12-C15-alkyl lactates, ethyl or butyl esters of citric acid or of acetylcitric acid, phthalic esters of longer branched alcohols such as bis(2-ethylhexyl) phthalate or phthalic polyesters, C2 to C18-dialkyl esters of C2 to C6-dicarboxylic acids, such as bis(2-ethylhexyl) adipate, dioctyl malate, diisopropyl adipate, aromatic and aliphatic sulfonic esters, such as C2 to C20-alkylsulfonic esters of phenol or of C1 to C18-alkanols and typical aromatic plasticizers such as polyphenyls, dibenzyltoluene, and isomer mixtures of C20 to C30 aromatics. It is said to be preferable to use mixtures of plasticizers of the ester type and of the aromatic type. A preferred mixture is a mixture of acetyl tributyl citrate and dibenzyltoluene.
The patent application additionally specifies plasticizers having molar masses exceeding 2000 g/mol. These plasticizers include different types of compounds, such as polyethers, polyesters, polycarbonates, polyolefins, in which the end groups are preferably hydroxyl, ether, alkyl and acyl groups.
The use of plasticizers makes it possible to avoid extreme mixing ratios in many indications.
A further advantage of the use of plasticizers is the fact that, as already described above, solid starter components can be readily dissolved in the plasticizers.
DE 197 11 514 B4, which is likewise aimed at impression materials, additionally states that customary plasticizers are generally of good compatibility with polyether materials, and so the use thereof is advisable not just for economic reasons but also for improving the properties, especially for avoidance or reduction of possible crystallization processes. Suitable examples were said to be phthalic esters, glycol derivatives, polymeric plasticizers, sorbitan esters, etc. Customary plasticizers were said to be described, for example, in “Polyethers, part I”, edited by Norman G. Gaylord, Interscience Publishers (1963). It is stated, however, that the addition of relatively large amounts of plasticizer to the impression materials can affect the water absorption, swelling and change in dimensions to such a degree that the impression becomes unusable.
DE 39 02 417 A1 discloses molding compositions for production of dental casting models. Here too, plasticizers are used. The publication refers to a “chemically inert” compound which is added to the compositions, “chemically inert” being understood to mean that the compound does not enter into any reactions with the organic polymerizable composition. The “chemically inert” compound thus does not have any functional groups reactive toward the polymerizable monomers, i.e. no double bonds such as polymerizable vinyl groups.
The publication specifies biphenyl, 1,2-diphenylethane, decanol, 2,4,6-trimethylnaphthalene, hexamethylbenzene, diphenylmethane, 1,1-diphenylethane, pentadecane, 2,3-dimethylbiphenyl, cinnamyl alcohol, dibenzyl ether, hexaethylbenzene and diethyl phthalate as suitable plasticizers.
DE 199 61 341 C2 is directed to temporary composite-based C&B materials, the aim being to improve fracture susceptibility with simultaneously high dimensional stability of these materials. The inventive compositions also comprise plasticizers in amounts of 1-40% by weight, preferably 2-30% by weight. The plasticizers should preferably have viscosities less than 10 Pas at 23° C. (cone-plate viscometer). Again polyethylene glycol derivatives, polypropylene glycols, low molecular weight polyesters, dibutyl phthalate, dioctyl phthalate, dinonyl phthalate, diphenyl phthalate, di(isononyl) adipate, tricresyl phosphate, paraffin oils and silicone oils are mentioned.
DE 197 54 029 A1 describes an elastic tooth restoration material and methods for producing tooth prosthetic material using the latter. In this application too, it is possible to use plasticizers. Preference is given to using phthalate plasticizers. Examples include phthalate derivatives, such as dimethyl phthalate, dibutyl phthalate and dioctyl phthalate.
DE 60 2004 009 552 T2 discloses an oral release system comprising an antibacterial agent and an inflammation inhibitor, which is suitable for the treatment of dental diseases, especially of periodontal diseases. In order to improve the flexibility of the system, a plasticizer or a mixture of plasticizers is added. It is said that type and amount of the plasticizer determines the flexibility of the composition. The following are mentioned as suitable plasticizers: phthalates such as dimethyl phthalate, dibutyl phthalate, diethyl phthalate, dibutyl sebacate, triethyl citrate, tributyl citrate, acetylated monoglycerides, acetyl tributyl citrate, triacetin, benzyl benzoate, glycol derivatives such as glycerol, polyethylene glycols, propylene glycol butyl, and/or glycol esters of fatty acids, refined mineral oils, oleic acid, castor oil, corn oil, camphor, and sugar alcohols such as sorbitol. Preferred plasticizers are sorbitol and glycerol, glycerol being the most preferred plasticizer. The preferred amount of plasticizer is in the range from 1 to 15% by weight and further preferably in the range from 4 to 10% by weight.
The patent claims a plasticizer selected from the group of glycol derivatives, phthalates, citrate derivatives, benzoates, butyl or glycol esters of fatty acids, highly refined mineral oils, camphor, oleic acid, castor oil, corn kernel oil and sugar alcohols.
DE 10 2008 283 306 A1 discloses a two-component, chemically curing, storage-stable dental composite material comprising nanodiamond. To establish particular properties, the inventive material may also comprise plasticizers.
The following are mentioned: polyethylene glycols, polypropylene glycols, unsaturated polyesters, phthalates, adipates, sebacates, phosphoric esters, phosphonic esters and/or citric esters.
DE 699 21 231 T2 describes a dental composition and a artificial tooth produced therefrom. This dental composition as well consists of a composite material, which means that it contains both an organic and an inorganic phase. The bond between the organic resin matrix and the inorganic filler surfaces is ensured with the aid of adhesion promoters. Examples of adhesion-promoting substances are organofunctional silanes, and titanate-based and zircoaluminate-based adhesion promoters. DE 699 21 231 T2 specifies several compounds for the various types of adhesion promoters. The amount of the adhesion promoter added to the dental composition is between 0.1 and 25 parts by weight per 100 parts by weight of the monomer. If the amount is more than 25 parts by weight, any excess of the adhesion promoter is said to act as a plasticizer.
DE 692 31 737 T2 relates to a root canal filling composition and to an adhesive composition. The heat-curable resin-based material of the inventive root canal composition also comprises a plasticizer in an amount between 0.1 and 30% by weight. The purpose of the plasticizer is to soften or to plasticize the resin, to such an extent that the material can readily be introduced into a root canal. The following are mentioned as suitable plasticizers: dibutoxyethoxyethyl adipate, dioctyl phthalate, dibutyl phthalate, butyl benzyl phthalate, alkyl benzyl phthalate, dialkyl adipate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, triphenyl phosphate and further esters.
The aim of DE 690 17 484 T2 is a chlorhexidine-containing composition for the treatment of periodontal or other diseases, wherein the chlorhexidine is to be released in a delayed manner. Again a plasticizer is used to regulate the flexibility of the final dried composition. The plasticizer must be provided in a sufficient amount to prevent the final composition from being too brittle. The plasticizer should be present in an amount of 0.01 to 15% by weight in the composition prior to drying. After the vaporization of 90% of the solvent, such compositions should contain 0.01 to 41% by weight of plasticizer. The following are named explicitly as plasticizers: phthalate esters, phosphate esters, glycol derivatives, hydrocarbons, oils or fatty acids, and glycerol and sorbitol have been found to be preferred plasticizers. The most preferred is glycerol.
DE 690 33 994 T2 also discloses liquid polymer compositions for prevention and treatment of dental or dermatological disorders. Again plasticizers are disclosed, for instance polyethylene glycol 400 to 4000, glycerol, sorbitol or mineral oil, which may be present in the compositions in concentrations of about 1% by weight.
DE 697 25 380 T2 describes liquid, light-curable compositions. According to the publication, such compositions are used to a wide extent as coating materials, as photoresists, as dental material or the like. For these compositions too, plasticizers are disclosed. Illustrative examples include dialkyl esters of phthalic acid, such as di-n-octyl phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate and di-2-ethylhexyl phthalate, triorgano esters of phosphoric acid such as tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate and tricresyl phosphate, dialkyl esters of adipic acid such as dibutyl adipate and di-n octyl adipate, and the like. The photocurable resin composition disclosed here may, in accordance with the invention, comprise one or a multitude of the plasticizers specified.
DE 698 01 010 T2 relates to a prosthetic restoration component with excellent biocompatibility, adequate hardness and mechanical strength, and methods for production thereof. Here the plasticizers disclosed for these systems are: phthalate esters (DOP, DEP, DBP), adipic esters, trimellitic esters and sebacic esters are mentioned.
DE 20 2010 014 676 U1 describes a duplicating composition which can also be used for production of negative impressions in the dental sector. According to the invention, this composition comprises 30 to 60% by weight of at least one polyhydric alcohol. The latter serves as a plasticizer and is supposed to contribute to the advantageous elastic properties of the negative impressions produced. The at least one polyhydric alcohol is preferably selected from the group comprising glycerol, sugar alcohols (e.g. sorbitol or mannitol), propylene glycol, polyethylene glycol and mixtures thereof, particular preference being given to the use of glycerol.
It is said to be particularly advantageous when the duplicating composition comprises 45 to 55% by weight of the at least one polyhydric alcohol, especially glycerol.
DE 199 41 738 B4 is aimed at polyurethane-based fillers for polymer formulations. As well as the inventive fillers, dental compositions formulated with the fillers may additionally comprise plasticizers to increase the flexibility of the compositions. Good suitability is said to be possessed, for example, by dibutyl, dioctyl and dinonyl phthalate, or dibutyl, dioctyl and dinonyl adipate, and also higher molecular weight polyphthalic esters and adipic esters.
DE 10 2009 046 251 A1 discloses a reactive one-component system. Such systems are of particular significance in the fields of sealants and adhesives. According to the publication, they can also be used in the medical sector, for example in the dental sector, in coatings such as lacquers or in reactive resins, for example road markings or industrial floors. The following are mentioned as plasticizers preferred for these one-component systems: esters, polyols, oils, low molecular weight polyethers or phthalates.
DE 2420351 C3 relates to the use of a composition as a root canal filling component. According to the publication, this dental composition requires an inert solvent (plasticizer) in order to dissolve the components and later to give rise to a polymer which can be removed again during a revision. Suitable compounds specified are water, glycerol and esters thereof, propylene glycol, 1,2-propanediol carbonate, pentaerythriol, diacetin, monoacetin, ethylene glycol, diethylene glycol and dipropylene glycol. However, within the examples of this patent diacetin (=glyceryl diacetate or 1,2,3-propanetriol 1,3-diacetate) is used exclusively.
For the use as plasticizers for the production of toxicologically favorable plastics the WO 00/78853 A1 specifies a whole series of cyclohexanepolycarboxylic acids and derivatives thereof. As well as the cyclohexanepolycarboxylic acids per se and derivatives thereof, especially mono-, di- or optionally tri- or tetraesters and anhydrides of the cyclohexanepolycarboxylic acids are proposed for use in plastics. The esters used are alkyl, cycloalkyl and alkoxyalkyl esters, where the alkyl, cycloalkyl and alkoxyalkyl groups may comprise generally 1 to 30, preferably 2 to 20 and more preferably 3 to 18 carbon atoms and wherein the alkyl residue can be linear or branched.
WO 00/78704 relates to selected cyclohexane-1,3- and -1,4-dicarboxylic esters, to the use thereof as plasticizers in plastics and to the preparation thereof by means of hydrogenation of the corresponding isophthalic and terephthalic esters by contacting one or more such isophthalic or terephthalic esters with a hydrogen-containing gas in the presence of a specific catalyst.
EP 1 042 273 B1 describes processes for hydrogenating benzenepolycarboxylic acids or derivatives thereof using a catalyst having macropores.
DE 28 23 165 specifies processes for preparing cycloaliphatic carboxylic esters.
The prior art regarding inert substances, or plasticizers in dental compositions or for production of toxicologically favorable plastics which, due to their low toxicity, would likewise be suitable as dental materials, thus describes a multitude of compounds.
With regard to use thereof in the dental sector, the plasticizers are utilized in one-component and multicomponent systems for a wide variety of different indications. They are used in free-radically crosslinkable systems, and likewise in drying or setting compositions. They are encountered in photocuring and chemically curing dental compositions. They are used in order to better (more exactly) blend multicomponent dental compositions and in order to optimize the properties of the resulting polymer. The plasticizing, flexibilizing effect of these inert compounds arises from the fact that the free, non-reactive chain ends of the plasticizers prevent a regular network structure. Their long chains distort and widen the structural framework. They may lie between the polymer chains and disrupt and prevent the formation of a majority of interactions between the individual molecular aggregates. Their mode of action is sometimes similar to that of a lubricant, which lies between the individual polymer layers and allows the polymers to slide past. The plasticizers are thus utilized as an elasticizing component in dental compositions which lowers the modulus of elasticity (and the glass transition temperature). In this context, it should be pointed out that the extent of the decrease in the mechanical strength of the materials in the case of use of many plasticizers from the prior art is disadvantageous.
In addition, plasticizers are also used in order to actively influence the reaction kinetics of a curable composition. For example, for temporary C&B materials, even in the case of systems with mixing ratios of 1:1, plasticizers are required since a sufficiently long elastic phase of the initially mixed composition is needed. It would be extremely difficult to achieve this without the use of plasticizers.